To help those still chasing the Swallow-tailed Gull today, and perhaps if/when it returns to the location on subsequent days, I made a map showing where the gull has been roosting, a few spots where you can scope from, and where you can access the beach at Richmond Beach Saltwater Park. It's at https://drive.google.com/open?id=1X7I0BsNTT84CgLc90OFf2oj8RSI&usp=sharing